OBJECTIVES: The WHO repeatedly stresses the importance of human capital and investing in health as a determinant of future economic growth. We describe a health care investment model that reflects the government perspective attributed to investing in rotavirus vaccination in Egypt, and how changes in morbidity and mortality influence government expenditure (education, health, allowances) over many generations. METHODS: The model applies a generational accounting approach for estimating the inter-temporal fiscal impact of policy changes. It accounts for direct fiscal transfers between age cohorts and the State during different life stages – childhood, school-age, working-age, and retirement – while simultaneously accounting for rotavirus medical costs, and how rotavirus mortality and morbidity influence government fiscal transfers. Costs are expressed in Egyptian Pounds (EGP; 1€=7EGP). The model is constructed using Egyptian life tables, rotavirus related and unrelated healthcare costs, employment earnings adjusted for age and social parameters. The model compares vaccinated and unvaccinated cohorts against rotavirus using discounted net tax revenues (gross taxes – transfers). RESULTS: Based on variations in rotavirus vaccine price, the model predicts health service savings mostly attributable to averting rotavirus treatment costs that could be achieved within 3–5 years and reaching EGP178 million obtained at year-5. The discounted net tax revenue between vaccinated and unvaccinated cohorts was EGP5.2 billion and EGP27.3 billion at year 25 and 50, respectively. Investing in rotavirus vaccination represented a 15% rate of return for government at year-50. Long-term government net tax revenues were insensitive to vaccine prices, although sensitive in short-term.  CONCLUSIONS: Health investment models are complementary to conventional economic evaluations of healthcare technologies. But they illuminate how government accounts, tax revenues, and expenditures are influenced by investing in healthcare programs. Investing in rotavirus vaccination could deliver early cost-offsets associated with reduced health care expenditure. It could increase future government net tax revenue attributed to lives saved.